I have tested the lines, the connections on this Burnham boiler and can't find the problem. The boiler is an older moldel that has been serviced each year by the same company. The boiler only works now -when I hit the red reset option. The boiler fires up to the temperature indicated on the thermostat and then shuts off. It does not refire when the temp drops. We have tested all the parts and connections out and they are in good shape.